Wheel emergency equipment



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ATTORNEY F. C. KEMBER WHEEL EMERGENCY EQUIPMENT May 19, 1953 Filed May 13, 194'? 14 Sheets-Sheet 2 INVENTOR. FEDERICO CARLOS KEMBER ATTORNEY May 19, 1953 F. c. KEMBER 2,638,997

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R E B M E K S O L R A C O C R E D E F ATTORNEY Patented May 19, 1953 UNITED STATES PATENT OFFICE WHEEL EMERGENCY EQUIPMENT Federico Carlos Kember, Buenos Aires, Argentina Application May 13, 1947, Serial No. 747,694

(ci. iso-) 16 Claims.

This invention relates to a wheel emergency equipment for vehicles in general.

As it is well known, the normal run of a vehicle may be affected by many factors, and particularly through lack of balance resulting from wheel skidding and tire punctures.

Amongst other, attempts to counteract the effects of tire deflation have been directed to means for supplying air, which, while theoretically acceptable, have not proved successful in practice.

On the other hand, in order to avoid sliding or skidding, the general tendency is to apply chains or other devices to the treads. These, although effective, can be used only on soft roads, inasmuch as for general use, such anti-skid devices would only be practical if they could be combined with means for readily attaching and detaching same.

Therefore, and in view of the difhculties encountered in the application of direct auxiliary means to the vehicle wheels, I have devised a wheel emergency assembly, wherein each main or road engaging Wheel of the vehicle is provided with an auxiliary wheel displaceable about the main wheel axle, occupying at least two positions thereby being retractile in one, and operative in another in case of failure of the main wheel.

For this purpose, each of the main wheels of the vehicle is provided with a mechanical device assuming a given non-operative position when the tire is under normal pressure; device which is capable of being displaced to an operative position when said pressure drops a certain degree, producing an effect which places said auxiliary wheel in contact with the ground, to support the vehicle.

Apart from being automatically responsive to punctures or deilations of the main wheel tires, said supplementary wheels may be rendered opative, at will, in case of emergency, and particularly when the vehicle is moving on slippery ground, so as to prevent skidding and secure stability of the vehicle, inasmuch as said supplementary wheels may be coupled to the vehicle engine.

Therefore, one of the main objects of the invention is to provide safety means capable of rendering an auxiliary wheel operative upon deflation or failure of the tire of the corresponding main wheel,

A further object of the invention is to minimize the danger of rolling over or undue deviations of the vehicle, inasmuch as either automatically or under the drivers control, the aux- 2 iliary or emergency wheels will become operative so as to secure the stability of the vehicle until the latter is brought to a stop. Said auxiliary wheels may also substitute the main wheels for driving the vehicle to a service station.

A further object of the invention is to provide means which will enable the driver to set in operation the anti-skidding means when the vehicle is running on slippery or muddy grounds, without having to leave his seat, inasmuch as he can render the auxiliary Wheels operative while the vehicle is moving on such grounds, and also retract them when the ground is normal, so that the vehicle may again be supported by the normal Wheels.

A still further object is to provide a system whereby the vehicle may act on any kind of ground, even on ice or snow, for which purpose said auxiliary wheels may be provided with special treads.

A still further object of the invention is to provide means for increasing the braking capacity of an automotive vehicle equipped with auxiliary wheels, whenever the brakes are applied with said auxiliary wheels in operation, due to the increased wheel surface in contact with the ground, which will increase adherence and thereby reduce skidding.

Other objects and advantages of this invention will become apparent from the course of the following detailed description, when read in conjunction With the accompanying drawings, illustrating preferred embodiments of the invention by way of example, and wherein:

Fig. 1 is a front view of an automotive vehicle equipped with emergency or supplementary wheels associated with the main road engaging wheels, showing the auxiliary wheels in retracted or inoperative position;

Fig. 2 is a radial section of a vehicle wheel, showing the device responsive to the fluid pressure in the tire;

Fig. 3 is a perspective view of one of the switches responsive to the action of the automatic device shown in Fig. 2 and corresponding to the closure of the alarm device circuit;

Fig. 4 shows a further switch responsive to the action of the automatic device shown in Fig. 2, said switch corresponding to the automatic operation of the supplementary vehicle wheel-s;

Fig. 5 shows one of the two switches responsive to the action of the automatic device shown in Fig. 2, corresponding to the automatic operation of the auxiliary driving wheels and associated with the hand controlled retracting circuit;

Fig. 6 is a plan view of an automobile chassis provided with the emergency equipment, said chassis being slightly modied so as to receive the auxiliary Wheels.

Figs. '7, 8 and 9 show three diierent examples of the mounting means for the auxiliary wheels, illustrating dierent ways of securing the passage thereof from an eccentric to a concentric position relative to the main wheels and Viceversa;

Fig. 10 is a schematic View of a further modication of the mounting means for the auxiliary wheel, similar to that shown in Fig. 7 but for passing from a position of considerable eccentricity to a position of slight eccentricity relative to the main wheel;

Fig. 11 is a detailed elevational view of one of the road-wheels and the auxiliary wheel therefor, in vertical diammetrical section;

Fig. 12 is a sectional elevation of the outer face of the supplementary wheel, taken along the lines |2--l2 of Fig. 11;

Fig. 13 is a sectional elevation taken along the lines l3-l3 of Fig. 11;

Fig. 14 is a sectional elevation taken along the lines M-I of Fig. 11;

Fig. 15 is a perspective view of the switch interpolated in the circuit of the electromagnet controlling the auxiliary road-Wheels shown in Figs. 1l, and 13;

Fig. 16 is a sectional View of a detail of the switch shown in Fig. 15, taken along the lines l6-l6 of Fig. 15;

Fig. 17 is a detailed sectional View taken along the lines l'l-ll of Fig. 16;

Fig. 18 is a partial and arbitrary sectional view of a further possible modication of the tread of the auxiliary wheels for the main road-wheels;

Fig. 19 is a vertical diammetrical section of the assembly of one of the main driving wheels and the corresponding' auxiliary wheel, showing the manner in which the latter is mounted and also the means connecting same to the main wheel, the auxiliary wheel being shown in retracted or inoperative position;

Fig. 20 is a schematic representation of one of the driving wheels, with the respective auxiliary Wheel in inoperative position;

Fig. 21 is a schematic representation of one of the driving wheels, with the corresponding auxiliary wheel in operative position;

Fig. 22 is a schematic section of the control mechanism through which the eccentric position of the auxiliary wheel becomes concentric;

Fig. 23 is a schematic detail of the required position of the electric switches responsive to the action of the automatic device depending on the deflation of the tire corresponding to the main driving wheel;

Fig. 24 shows a section of the auxiliary driving wheel, taken along the lines 24-24 of Fig. 19;

Fig. 25 is an arbitrary schematic view showing the manner in whi-ch the Icontrol cylinder, for setting in operation or retracting the auxiliary driving wheel, receives and transmits the action of a drive gear. This view shows the time in which the displacement is being eiected, viz; at a point between the operative and inoperative positions;

Fig. 26 is a partial schematic view corresponding to the mounting of the clutch between the main driving wheel and the corresponding auxiliary wheely taken along lines 25-26 in Fig. 19;

Fig. 27 is a schematic view of the casing in Which are found the emergency switches interpolated in the different circuits for the operation driving wheels;

Fig. 28 is a cross-sectional view taken along along the lines 28-28 of Fig. 6 and schematically showing the mounting of the slider controlling the switches shown in Fig. 27;

Fig. 29 is a detailed view of the switch shaft according to one of the embodiments, for dening the two positions required for the operation thereof, according to the action of the slider;

Fig. 30 is a sectional View of the same hand actuated commutator switch, taken along line 30-30 of Fig. 31;

Fig. 31 is a top view of a hand actuated commutator switch;

Fig. 32 is a further sectional view of the hand actuated commutator switch, taken along line 32-32 of Figs. 30 and 31;

Fig. 33 is a schematic perspective view of the hand actuated commutator switch contacts, shown in Figs. 30, 31 and 32;

Fig. 34 is a general diagram of the electrical circuits for setting in operation and retralcting the auxiliary road-wheels and driving wheels, which are shown in full lines in inoperative position, and in dotted lines in operative position. The `circuits have also been combined with some schematic mechanical details.

The same reference characters are used to indicate like or corresponding parts or elements throughout the drawings.

As may be seen in the drawings, a is the chassis of the vehicle, b are the front or road-wheels and c the rear wheels which in this instance are the driven wheels inasmuch as the corresponding engine l of the vehicle derives the action thereof towards the differential 2 (Figs. 6 and 34) from which the half-axles 3 extend to the respective wheels c.

Each of said front wheels b is provided with a supplementary wheel d, while each of the driving wheels c is provided with an auxiliary wheel c forming with said auxiliary Wheels d the equipment subject of this invention and actuated through an electric circuit to be described hereinafter.

Broadly, the invention comprises a wheel emergency equipment ycombined with electric circuits which are normally open and which are automatically closed upon a reduction in the fluid pressure in the tires, through puncture or other failure, so as to set into operation the auxiliary wheels. In certain cases, the driver may place said auxiliary wheels into operation at will, by means manually action operated, capable of closing said cir-cuits.

In order to warn the driver of such failures, the equipment also comprises an optical and sound alarm system acting a certain time before the auxiliary or emergency wheels are placed in operation.

The automatic closure of said circuits is obtained through the action of a device indicated at and particularly shown in Fig. 2. Each main wheel b or c is provided with at least one of the devices f. Said device f is classied as automatic inasmuch as it is combined with the Wheel tire so that a drop in pressure in the inner tube 4, the tire of which is indicated at 5, whether through leakage or puncture, will place in operation the corresponding auxiliary wheel d of the main wheels b, and e of the main wheels c.

Said automatic device ,f comprises a stem 6 adapted in a guide I of a bracket 8, and as may be seen in the drawings, said stem 6 passes through the rim I by means of a perforation 9 and ends in a shoe II engaging the inner tube 4 of the wheel tire. Stem 6 is urged radially by spring I2, the resistance of which is overcome by the normal pressure in the inner tube, so that said stem 6 and shoe I I are normally held in the position shown in full lines. As the tension of Said spring I2 is capable of overcoming the pressure in the tire when said pressure falls below a predetermined value, upon a sufficient drop in the fiuid pressure the spring tension prevails and overcomes the walls of the inner tube 4, with a corresponding displacement of stem 6 and shoe II thereof. Consequently, in the case of a puncture or a loss of part of the fluid contained in said inner tube 4, said stem 6 will be displaced to the positions shown in dotted lines in Figs. 2, 11 and 19.

Stem 46 is provided with a stud I3 rotating with the wheel, so that on being radially displaced it will successively strike against levers I4 and I5 holding switches g and h in open position. Both switches g and h, together with levers I4 and I5 are mounted on a bracket I6 on wheels b (Fig. ll) and II on wheels c (Fig. 23). Both brackets will be described in detail hereinafter.

Switches g and h are of the same construction. Switches h of the driving wheels c differ from those of the road-Wheels b in their electric connections and are therefore identified as switches h. Switch g is shown in Fig. 3, switch h in Fig. 4 and switch h' in Fig. 5.

Switch g, Fig. 3, comprises a casing I8 containing three pairs of resilient fingers I9, 26 and 2|, located near the wall I8 of casing I8. Lever I4 of casing I8 extends through the wall I8" of said casing and is pivoted at 22, The end I4 of said lever is located Within the path of stud I3 of device f, as will be explained later.

The end I4 of lever I4 is made of conductive material and is electrically insulated from the remainder of lever I4. During the angular displacement of said lever, the end I4" thereof will register with the pairs of fingers I9, 20 and 2|. The fingers forming each pair are spaced by a distance which is smaller than the thickness of said end I4, but inasmuch as said ngers are resilient, they are capable of receiving said end I4, which enters therebetween with a wedge action and is effectively held between the pairs of fingers I9, 2U or 2l. The pairs of fingers I9 and 2I are contacts of switch g.

The purpose of the two fingers 20 which are centrally located, is to hold lever I4 in an intermediate or normal position, shown in full lines in Fig. 3. Each of the contact fingers I9 and 2 I, together with the end I4 of lever I4, forms a switch in a single electrica1 circuitl Thus, when lever I4 is in the position |4', the end I4 thereof will be interposed between the two contacts I9 and will act as an intermediary for closing the circuit, whereas when said lever I4 assumes the position I4", the end I4" thereof will be interposed between the two contacts 2l and will act so as to close the same circuit.

Switch h (Fig. 4) which is similar to switch y, comprises a casing 23 against the Wall 23 of which are arranged in an arc the pairs of fingers 24, 25 and 26. A lever I5 extends through the wall 23" of said casing and the end I5 thereof is located in the path of stud I3 of the device f. Said lever I is pivoted at 2'I.

The end l5l of lever I5 is made of conductive material and is electrically insulated from the remaining portion of lever I5. In the angular displacement of said lever, the end I5" thereof registers with the pairs of fingers 24, 25 and 26. The fingers forming each pair are spaced by a distance which is smaller than the thickness of said end I5, but inasmuch as said fingers are resilient, they are capable of receiving said end I5 which enters and is effectively held between them with a wedging action,

The pair of fingers 25 which are centrally located are intended to hold the lever I5 in the intermediate or normal position shown in full lines in Fig. 4, whereas each of the remaining pairs 24 and 26 forms, together with said end I5"I a switch for a single circuit. Thus, when lever I5 assumes the position I5"', the end I5 interposed between ngers 24 acts as an intermediary in closing the circuit, whereas when lever I5 assumes the position indicated at I5, the end I5 interposed between fingers 26 acts so as to close the same electric circuit.

When the tire of wheel b or c is under normal pressure, it will hold spring I2 contracted and thus stud I3 will be held in the inoperative position shown in full lines in Fig. 2, whereby upon wheel b or c being rotated, said stop I3 will also rotate together with device f and will not engage levers I4 and I5. Lever I4 is located at a point adjacent the inoperative position of stud I3, while lever I5 is located at another point further away from the wheel axle.

When the fluid pressure in tire 4 decreases sufliciently, spring I2 will overcome the tire pressure and cause the displacement of stem 6 which forms part of device f and rotates with wheel b or c, and inasmuch as levers I4 and I5 are associated with fixed casings, upon stud I3 reaching the position I 3 corresponding to the circular path in which the end of lever I4 is located, it will engage and shift same from the position I4 shown in full lines in Fig. 3 to the position I4 shown in dotted lines, when the vehicle is moving forward; said end I4 remaining as a bridge between the contacts of pair I9; or towards position I4 when the vehicle is moving backwards, in which case the end I4", of lever I4 will close the circuit between the pair of contact fingers 2I. As may be seen in Fig. 3, when lever I4 assumes either of these positions I4"' or I4', it will remain out of reach of stud I3. Both positions imposed by stud I3 close the automatic alarm circuit, the elements of which will be described hereinafter.

If the fluid pressure continues to fall, stem 6 with shoe II reaches position II" (Fig. 2) wherein stud I3, assuming position I3, engages lever I5, shifting same to cause the closure of the circuit, thereby moving the corresponding auxiliary wheel from the inoperative to the operative position thereof.

Switches g and h, described above, correspond only to the automatic action. Inasmuch as switch h acts in exactly the same manner as switch h as regards the automatic circuit, it has been given the same reference characters as switch h; it only differs from the latter in that the pair of intermediary fingers 25 of Switch h' does not act as a simple holding means but also as a switch for the electric circuit for operating the equipment at will.

As stated hereinbefore, the purpose of the equipment is to provide each main wheel of the Vehicle with an auxiliary wheel capable of replacing same and of performing all the functions corresponding to a main wheel, whereby the driver may run the vehicle on the auxiliary accesar wheels, if necessary, until he finds suitable time and place to repair the failure. Also, said auxiliary driving wheels may, as already stated, act as complementary wheels, as the driver may at any time set said auxiliary wheels into operation through hand controlled commutating means.

In order that an auxiliary wheel may act as eiectively as a main wheel, it should be similar or substantially similar to said main wheel, i. e. it should be of sufficient diameter for a normal rolling and capable of acting as a road-wheel when replacing a road-wheel, and as a driving vwheel when replacing a main driving wheel.

For this purpose, the auxiliary wheels d and e are so arranged as to have within their perimeter the axle of the main wheel, and in view of the mounting thereof, they are capable of assuming two positions, viz; an eccentric position relative to the center of the axle of the main wheel, said eccentricity being in a direction opposite the ground relative to the axle; this position corresponds to the retracted or inoperative position of the auxiliary wheel. The other position is a concentric position, or a position oi slight eccentricity relative said axle of the main wheel and corresponds to the operative position of the auxiliary wheel.

The schematic representations of Figs. 7, 8 and 9 show three embodiments of the mounting means for the auxiliary wheel, with different means for shifting same from the eccentric to the concentric position relative to the main wheel. The schematic representation of Fig. 10 shows a further embodiment of a mounting means similar to that of Fig. 7 but for shifting from a position of considerable eccentricity to one of slight eccentricity relative to the main wheel.

In the embodiment of Fig. '7, the reference numeral 3 indicates the cross-section of an axle, the center 3 of which is given by the intersection of lines 28-28 and 29-29. Said axle is surrounded by a jacket 30.

The desired degree of eccentricity is the distance between point 3 and point 3| along line 29-29. One half of this magnitude is taken, and starting from point 3, point 32 is marked in the direction of the desired eccentricity. A circle is traced, taking point 32 as the center, with a radius equal to the distance 3-32 plus one-half the diameter of axle 3 with jacket 30 thereof. This circle is materialized by the core 32 of the eccentricity, said core being fixed to jacket 30 and therefore not movable. Now, with the center at 3| and the radius of the auxiliary wheel, a circumference is traced, indicated at 33, which represents the tread of said auxiliary wheel.

If this circumference 33 with its center at 3l by revolved 180 about the xed core 32, so as to assume the position shown in dotted lines 33 where it contacts line 34 representing the ground, the imaginary center thereof would pass from point 3| to point 3', thus becoming concentric relative to axle 3. If an annular band 35, having a circumference 33, is capable of rotating on the central part 36 of said circumference 33, the band 35 would become a wheel proper. In the position shown in dotted lines 36', said part 36 will constitute the axis of rotation for said band 35. The entire portion shown in dotted lines corresponds to the operative position of the Wheel, while the portion shown in full lines corresponds to the retracted or inoperative position.

Fig. 8 shows a diierent mounting means capable of producing the same result of that illusn trated in Fig. 7. The point 3', given by the intersection of lines 28-28 and lines 29-28 -is the center of the section of an axle 3. Point 3l, on 29-28 represents the imaginary center of a supplementary wheel when in eccentric or retracted position. Point 38 is the center of an eccentric body 38 having a perforation 39 which is arcuate and of a width slightly larger than that of aXle 3.

If said body 38 should rotate about point 38', as indicated by arrow 40, at the end of the travel thereof, it will locate the imaginary point or center 31 registering with the center 3 of axle 3. Thus, the auxiliary wheel, the tread of which is indicated by means of line 33, will pass from an eccentric position shown in full lines, to a concentric position relative to said axle, shown in dotted lines, wherein it will contact the ground line 34.

Fig. 9 illustrates a further system in which the result achieved by the means shown in Figs. '7 and 8, may be obtained. Point 3 determined by the intersection of lines 28-28 and 29-29 is the center of an axle 3. Point 4l is the imaginary center of a wheel the tread of which is indicated at 33 in an eccentric position relative to said axle 3. Reference numeral 42 indicates a circular body having its imaginary center at 4l. Should said body 42 have a perforation such as that indicated at 43, with a suitable force acting alternatively in the directions shown by the double arrow 44, it will be capable of passing circumference 33 from eccentricity to concentricity relative to axle 3, and vice-versa.

In the embodiment of Fig. l0, reference numeral 45 indicates the center of axle 45 of the main wheel. In the vertical line 48-48 a point of major eccentricity is determined by numeral 41, while reference numeral 48 indicates a minor eccentricity relative to the center 45. With the point determined by reference numeral 49 half the distance between points 47 and 48 is dened. Said point 49 is the center of the circle materialized by core 49, within which is comprised the circle corresponding to center 45 of axle 45, which is tangential.

Point 41 constitutes the center of circumference 5D representing the tread of the auxiliary wheels. Upon revolving said circumference 50 towards position 50 indicated in dotted lines, since said shifting is made with the center of rotation at point 49', the center of said circumferential line in the position shown in dotted lines will be point 48, which is less eccentric relative to the center 45 of axle 45.

Of the eccentrical mounting means for the supplementary wheels as explained above, those shown in Figs. 7 and 10 are preferred, inasmuch as they are safer, apart from other advantages for mechanical combinations.

Considering iirst the road-wheels, in the case of a shift of the auxiliary to the concentric position, because of pneumatic emergency, there would be two wheels contacting the ground on the side of abnormality, viz; the main wheel and the auxiliary wheel. This would cause an overloading of such side on the steering of the vehicle, tending to deviate the direction thereof. If through suitable means both auxiliary roadwheels are lowered, this lack of equilibrium would not occur but, the steering would become much heavier. On the other hand, if the auxiliary wheels are mounted as shown in Fig. 10, the imaginary axis of said auxiliary wheels will shift to a position (48) below the axis of the main wheel at the time of the emergency, and, by lowering both at the same time. the auxiliary wheels will take the place of the main wheels, since the latter will remain out of contact with the ground. The wheels will have thus automatically changed, without deviations of the vehicle and without any difference in steering easeness or behaviour of the auxiliary wheels.

In the case of the driving wheels, it is desirable to have the auxiliary wheels act in place of or as additional to the main wheels, as required by circumstances. In place of the main wheels in case of uid pressure failure and in addition to the main wheels when it is desired to afford more contacting surface with the ground; hence an improved adherence, thereby providing the possibility of quickly braking the vehicle with less risk of skidding on wet, muddy or snow-covered roads, particularly when the tread of the auxiliary wheel is of suitable composition and structure.

Furthermore, because of less use, this tread will be better preserved than that of the main or normal wheel.

In the case of an excessive load being imposed on the rear axle, the auxiliary wheels can share such load, thereby improving the operation of the vehicle and reducing wear of the main wheels. In the case of trucks, said auxiliary wheels may be retracted when the vehicle is empty or with light freight, thereby avoiding useless wear of the tires. All this is only possible when the auxiliary wheel passes from an eccentric inoperative position to a concentric operative position, thereby becoming supplementary or complementary according to the case.

In Fig. 11, showing a road-wheel, it may be seen that the mounting is eiected on the end of axle 45 xed to a plate 5l, serving as a base for the brake, comprising cylinder 52 and brake band eccentricity adjusting nuts 53 of wheel b, in the usual manner. However, in order to allow for said auxiliary wheel, said axle end 45 extends inwardly to another plate 54 which is eccentric relative to said axle end 45, and constitutes the fixed base of the supplementary wheel d, said plate 54 having the linkage 55 corresponding to the steering of the vehicle.

As shown in Figs. 11 and 12, the core 49 to which said plate 54 is fixed, is arranged eccentrically relative to axle end 45 and wheel b. Said core 49 constitutes the mounting means for the auxiliary wheel d, but in an indirect manner since a disc 56 is interposed between core 49 and said wheel. Disc 56 is eccentrically mounted on core 49 and by means of balls or rollers 5l, allows the free rotation of the respective wheel d. Said disc 56 is associated with core 49 by means of balls or rollers 58.

The rotary portion of wheel d comprises an annular piece 59 adapted to disc 56 by means of said balls l, while on the other hand said annular piece 59 adapts a rim 60 serving to support the tire of wheel d.

Inasmuch as said core 49 acts as an eccentric shaft for disc 56, said disc is capable of rotating 180, so as to change the direction of the eccentricity relative to the center 49', whereby wheel d may be shifted from the inoperative position shown in full lines in Figs. 11 and 12, to the operative position indicated in dotted lines in said figures, wherein the center of wheel d will be near the center 45 of the axle end 45.

In order to effect this change or motion, said disc 56 is provided with a gear 6l the teeth of which are directed towards the center thereof. As shown in Figs. 11, 12 and 13, said gear 6| meshes with a pinion 62 iixed to a tubular shaft b3 mounted rotatably about the shaft end 45 and carrying an electromagnet i the coil 64 of which is provided with an axial perforation housing a movable core 65 having a stem 65 provided with a 1in 66 opposite a meshing crown 6l. Said crown 6l is attached to plate 68 forming part of the rotary frame of wheel b.

The rotary frame b of wheel b comprises the usual brake -drum 69 enclosing the brake members mounted on plate 5I.

The core 65 of electromagnet z' is urged .by means of a spring 'I0 towards an unmeshing position, viz; to a position wherein fin 66 is out of engagement with crown 6l. In this position, core 65 will prevent the displacement of electromagnet i upon said core engaging a notch ll.

This engagement serves through electromagnet i, tubular shaft 63 and pinion 62, as a holding means for retaining auxiliary wheel d, in the inoperative position, due to pinion 62 holding gear 6l which is integral with disc 56.

Coil 64 of electromagnet z' carries on the respective terminals thereof two brushes l2 and 13, engageable with annular contacts i4 and l5 on box '16 fixed to core 49. Said annular contacts are fed by leads l1 and 18 extending from switch h, Figs. 4, 11, and 34, having a lever i5 the end l5 of which is located, as explained above, in the path of stud I3 of device f when said stud assumes the position I3 (Fig. 2) upon a deflation of tire 4. The circuit of electromagnet i (Fig. 11) is closed by the pairs of contacts 24 and 26 when the end l5" of lever l5 is received by said contacts.

Thus, switch his one of the switches of electromagnet z' and upon a puncture and/or defiation of tire 4, said stem 6 will be displaced through the action of spring l2. y On reaching the position I3, stud I3 will actuate lever l5 and close the circuit of electromagnet z', which will overcome the tension of spring 'l0 and attract core 65, placing fin 66 against crown 61 (see Fig. 14). Since said crown is attached to frame b of the rotating wheel b, it will cause the rotation of electromagnet z therewith, together with tubular shaft 63, the pinion 62 of which will actuate gear 6l. Gear 6l forming part of disc 56, the latter will be set in motion and displaced from the position shown in full lines in Fig. 12 to the position shown in dotted lines in the same Fig. 12. Disc 56 is provided with a tooth 19 which in reaching the upper position, from that shown in Fig. 12, will actuate switch j also interpolated in the circuit of electromagnet i, whereby said tooth i9 will interrupt the circuit of said electromagnet precisely at the time wheel d is in the operative position shown in dotted lines in Figs. 11 and l2, and inasmuch as spring 10 will move 1in 66 out of engagement with crown 6l upon the circuit of electromagnet i being opened, the auxiliary wheel d will remain firmly in position, acting in place of the main wheel b.

As shown in Figs. 15, 16 and 17, switch y' comprises a lever 8D the pivot 8l of which is provided with a lug 82 located within the path of tooth 19. Said lever is provided with an intermediary contact 80 which when in the position shown in full lines in Fig. 15, connects the pair of contacts 83 included in the circuit of electromagnet z', whereas when in the dotted-line position, said lever 80 is engaged by clamping memthe flange 88" of cap 88 (Fig. 11).

' housing is thus formed between box 16 and cap 88.

cease? il. bers 84 and 85,-respectively. For the purpose of holding the circuit-closing position, said pivot 8| is provided with a prismatic head 8| engaged by leaf springs 86 and 81. Said leaf springs 86 and 81 complete the displacement initiated by lever 80.

The outer face of disc 56 is provided with a cap 88 which is concentric relative to core 139 and the cavity of which serves as a base for said gear 6|.

The diameter of cap 88 is substantially larger than that of gear 6|, thus leaving an annular space between them, in which is housed a shockabsorbing and braking `device lc. Said device k does not bear against the body of cap 88 but is provided with brackets 89 and 90 indirectly mounted on core 49.

As shown in Fig. 12, said device lc comprises as a main member a bow spring 9|, the ends of which are secured to the respective brackets 89 and 90. Said bow 9| is provided with a pair of resilient lugs 92 and 93 the ends of which face each other and are spaced so as to provide a gap 94 adapted to receive a tooth 95 on the outer face of gear 6|.

Said lugs 92 and 93 are sufciently resilient as to be overcome by the tooth 95 when the latter is displaced in either direction, but are also sufciently strong to hold said tooth when it engages gap 94.

Bow 9| is provided with a pair of brake shoes 96 and 91, one of which, 96, is located between lug 92 and bracket 89, while the other shoe 91 is located between lug 93 and bracket 90.

When tooth 95 engages gap 94, it will still be affected by the inertia of the displacement thereof, and will act against the end of one of the lugs 92 or 93, deforming bow 9| until one of the shoes 96 or 91 contacts the inner face of cap 88, thereby causing a frictional braking effect. Due to the opposed tension of the two halves of bow 9|, both lugs 92 and 93 will determine, in gap 94, the final position of tooth 95 and hence the operative position of auxiliary wheel d, shown in dotted lines in Figs. 11 and 12.

In the operative position of the auxiliary wheel d, it will replace the main wheel b, raising the latter from the ground as a result of the slight eccentricity of wheel d relative to wheel bi. The height at which wheel b will remain with respect to the ground is indicated by the magnitude 98 in Fig. 10.

In Fig. 11, the operative position shown in dotted lines indicates the manner in which the main wheel b remains in a raised position when the auxiliary wheel d is rendered operative.

Cap 88 is provided with a shoulder 88' capable of being engaged by n 82 of pivot 8| of switch y, and inasmuch as said tooth 19 is carried by said shoulder, the n 82 will thus remain within the path of tooth 19.

Said cap 88 is also provided with a surrounding flange 88 and as shown in Fig. 15, said box 16 is provided with a visor-shaped member 99 eccentrically circumscribed to the section of box 16, so as to form, together with edge 16 of said box 16, a flange 99 provided with a felt member by means of which it is adapted against A shielded In order to have access within said housing, said member 99 is provided with a pair of openings `||J| and |02 (Fig. 13) registering respectively with lugs 92 and 93, so that after the main Wheel b is removed for repair, the auxiliary wheel d (after jacking up the corresponding end of the vehicle) may be returned to the inoperative position by freeing the tooth from one of the lugs 92 or 93, which may be done by means of a suitable tool.

Said visor-shaped member 99 serves as a base for bracket |6 of switches g and h, and the outer face of said member 99 supports switch y', as may be seen in Fig. 11.

Inasmuch as the auxiliary wheel d covers the inner face of the main wheel b, as shown in Fig. 14, the frame supporting plate 68 is provided with openings |03 affording access to the drain tube |84 of brake cylinder 52 and eccentric nuts 53 of said brake system. A pipe |05 for hydraulic brake liquid passes through the auxiliary wheel d, extending through a longitudinal channel |05 on axle end 95 (Fig. 1l).

Fig. 18 is a schematic representation of the manner in which the tread of the auxiliary roadwheels d may also be constituted by a disc holding a non-pneumatic tire. It is obvious, however, that the tread of the auxiliary wheels may have any desired construction.

In Fig. 19, illustrating the case of a driving wheel, it will be seen that the half-axle 3 extends from the corresponding differential 2, included in a sleeve 30, until it joints the frame c' of the corresponding wheel c, while sleeve 30 is attached to the fixed plate |06 where the brake, constituted by hydraulic cylinder |01 and shoes |08, is mounted.

Inasmuch as the auxiliary wheel e is mounted as indicated in Fig. '1, it is provided with a mounting core 32 which is eccentric relative to halfaxle 3 and so fixed to sleeve 30 that the latter remains within the area of core 32 with which it is internally tangential.

Said core 32 is provided with a set of rollers |09 by means of which said body 36 is eccentrically adapted, said body 36 acting by means of balls or rollers I0 as a shaft for the rotation of wheel e constituted by a frame 35 carrying a rim to which the tire ||2 is adapted.

Said body 36 is provided with an electromagnet m the coil ||3 of which has an axial perforation wherein is housed a movable core H4 having a stem-like extension ||5 terminating in a shoe ||6. Said core llll is urged towards the center of core 32 by means of a spring 1, and as shown in Figs. 19 and 24, when wheel e is in inoperative position, said shoe H8 engages a notch ||8 on core 32, while in the operative position of the auxiliary wheel e, shown in Fig. 2l, and in dotted lines in Fig. 24, said shoe engages a notch ||9 located at from notch IIS on said core 32.

Concentrically located around core 32 is a cylinder |20 which is mounted in a bore in body 36 by means of rollers |2|, as shown in Figs. 19 and 22, allowing cylinder |28 to rotate independently of body 36. However, said cylinder will act as an indirect means for driving body 36, as upon said cylinder being rotated, shoe |I6 will act as intermediary means on being connected through attraction of electromagnet m, in the circuit.

For this purpose, shoe ||6 is provided with an extension disposed angularly with respect to stem ||5 and having a contact surface H6' facing the inner surface of said cylinder |20.v

Cylinder |29 is provided with a gear having inner teeth |22 meshing with a pinion |23 located at the end of a tubular shaft n. Said shaft n corresponds to the right-hand side of the vehicle, as the left-hand side tubular shaft is indicated by n. Said shafts n and n surround the cor- 

